buf := make([]byte, 3) // All runes in this test are 3 bytes long
	r := NewReader(&StringReader{data: []string{"日本語日本語日本語"}})
	if r.UnreadRune() == nil {
		t.Error("expected error on UnreadRune from fresh buffer")
	}
	_, _, err := r.ReadRune()
	if err != nil {
		t.Error("unexpected error on ReadRune (1):", err)
	}
	if err = r.UnreadRune(); err != nil {
		t.Error("unexpected error on UnreadRune (1):", err)
	}

variables, only on lexical <i>references</i> to them in the source,
analyzed transitively. For instance, if a variable <code>x</code>'s
initialization expression refers to a function whose body refers to
variable <code>y</code> then <code>x</code> depends on <code>y</code>.
Specifically:
</p>

<ul>
<li>
A reference to a variable or function is an identifier denoting that

</p>

<pre>
type T1[P T1[P]] …                    // illegal: T1 refers to itself
type T2[P interface{ T2[int] }] …     // illegal: T2 refers to itself
type T3[P interface{ m(T3[int])}] …   // illegal: T3 refers to itself
type T4[P T5[P]] …                    // illegal: T4 refers to T5 and
type T5[P T4[P]] …                    //          T5 refers to T4

references to the virtual stack pointer from references to the architectural
<code>SP</code> register.
That is, <code>x-8(SP)</code> and <code>-8(SP)</code>
are different memory locations:
the first refers to the virtual stack pointer pseudo-register,
while the second refers to the
hardware's <code>SP</code> register.
</p>

<p>
On machines where <code>SP</code> and <code>PC</code> are
traditionally aliases for a physical, numbered register,

</p>

<p>
  <code>mymod/mypack    coverage: 0.0% of statements</code>
</p>

<h3 id="trace">Trace</h3>

<!-- https://go.dev/issue/63960 -->
<p>
  The <code>trace</code> tool's web UI has been gently refreshed as part of the
  work to support the new tracer, resolving several issues and improving the
  readability of various sub-pages.
  The web UI now supports exploring traces in a thread-oriented view.